Agents for preserving technical materials against insects

ABSTRACT

The use of the compounds of the formula (I)                    
     as agents for preserving technical materials against insects.

This application is a continuation of application Ser. No. 07/872,279,filed on Apr. 22, 1992 now abandoned.

The present invention relates to the use of known nitromethylene ornitroimino compounds as agents for combating technical materialsdestroying insects in order to preserve these materials.

The present invention also relates to compositions useful for combatingthese insects, preserving technical materials completely, i.e. not onlyagainst insects but also against fungi, bacteriae and algae and fortreating soil to protect technical materials against termiteinfestations.

The invention furthermore relates to processes for treating technicalmaterials and for soil treatment against termite infestations.

The compounds and their insecticidal use in the field of plantprotection has already been known. Compare for example with EP-A 163855and EP-A 192060.

Insecticidal agents and compositions of said compounds and their use topreserve technical materials completely and to treat soilagainst-termite infestations have not been known up to now.

Different insects are known as pests infesting technical materials sothat due to serious damages caused thereby undesirable effects on livingenvironment and cultural assets principally made of these materials haveposed a social problem, urgently requiring effective controlling of thepests. Termites are known as important examples of these pests.

At present, use for combating technical materials destroying insects hasbeen made of organophosphorus insecticides such as phoxim[0-(α-cyanobenzylideneamino)0,0-diethylphosphorothioate], chloropyriphos[0,0-diethyl-3,5,6-trichloro-2-pyridylphosphorothioate], etc., as wellas pyrethroides series insecticides such as permethrin[5-benzyl-3-furylmethyl-3-(2-methoxy-carbonyl-1-propenyl)-2,2-dimethylcyclopropanecarboxylate], decamethrin [α-cyano-3-phenoxybenzyld,l-cis-3-(2,2-dibromovinyl)-2,2-dimethyl cyclopropane carboxylate],cypermethrin [α-cyano-3-phenoxybenzyl (±) cis,trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate],fenvalerate [(RS)-α-cyano-3-phenoxybenzyl(RS)-2-(4-chlorophenyl)-3-methylbutyrate], cyflutrine[cyano-(4-fluoro-3-phenoxyphenyl)methyl-3-(2,2-dichloroethenyl)-2,2-dimethyl-cyclopropane carboxylate].

However, the above-mentioned insecticides are unsatisfactory as far aseffective concentration and the long lasting effect are concerned.

It has been found that the known compounds of the formula (I)

wherein X is NH or S,

Y is CH or N

Z is 2-chloro-5-pyridyl or 2-chloro-5-thiazolyl,

R¹ is hydrogen or methyl, and

n is 0 or 1,

exhibit powerful insecticidal properties on material destroying insectsand preferably on termites.

The compounds according to the invention of the formula (I) surprisinglyexhibit an extremely strong insecticidal action on material destroyinginsects and the function is substantially superior to that of knowninsecticidal agents.

The compounds of the formula (I) can be used to preserve technicalmaterials against insects.

In the formula (I), the individual residues have the followingpreferable meanings:

X is NH or S,

Y is CH or N,

Z is 2-chloro-5-pyridyl,

R¹ is hydrogen, and

n is 0 or 1.

As examples of the active substances to be used according to theinvention, the following ones are particularly preferred:

1-(6-chloro-3-pyridylmethyl)-2-nitromethylene-imidazolidine,

3-(6-chloro-3-pyridylmethyl)-2-nitromethylene-thiazolidine,

1-(6-chloro-3-pyridylmethyl)-2-nitroimino-imidazolidine,

1-(6-chloro-3-pyridylmethyl)-2-nitromethylene-tetrahydropyrimidine, and

3-(6-chloro-3-pyridylmethyl)-2-nitromethylene-tetrahydro-2H-1,3-thiazine.

The active substances to be used according to the invention exhibitpowerful insecticidal effects against material destroying insects.

They can therefore be used in insecticidal agents for combating materialdestroying insects and preserving technical materials. They can also beused for soil treatment against termite infestation.

As individual examples of technical materials preserved by means of theinsecticidal agents according to the present invention the followingones can be mentioned: wood or composite wood-materials (such as pressedwood, particle board, chip board, wafer board, plywood, wood laminatedmaterial, freshly cut timber/lumber etc.), paper,leather or leatherproducts, natural or synthetic polymers, textiles.

Preferable materials are wood or composite wood-materials.

As individual examples of insects to be combated or controled by theactive substances of formula (I) according to the present invention thefollowing ones can be mentioned:

Order Isoptera

Mastotermitidae

Kalotermitidae such as Kalotermes spp.

Cryptotermes spp. etc.

Termopsidae such as Zootermopsis spp. etc.

Rhinotermitidae such as Reticulitermes spp.

Heterotermes spp.

Coptotermes spp. etc.

Termitidae such as Amitermes spp.

Nasutitermes spp.

Acanthotermes spp.

Mikrotermes spp. etc.

Order Coleoptera

Lyctidae such as Lyctus brunneus etc.

Bostrychidae such as Bostrychus capucinus

Dinoderus minutus etc.

Anobiidae such as Anobium punctatum

Xyletinus peltatus

Xestobium rufovillosum

Ptilinus pectinicomis etc.

Cerambycidae such as Hylotrupes bajulus

Hesperophanus cinereus

Stromatium fulvum

Chlorophorus pilosus etc.

Oedemeridae

Serropulpidae

Curculionidae

Seolytida

Platypodidae

Order Hymenoptera

Siricidae such as Sirex spp.

Urocerus spp.

Formicidae such as Camponotus spp.

In the above Isopterous insects, especially, there may be mentioned asexamples of termites in Japan:

Deucotermes speratus,

Coptotermes formosanus,

Glyptotermes fucus,

Glyptotermes satsumensis,

Glyptotermes nakajimai,

Glyptotermes Kodamai,

Incisitermes minor,

Neotermes koshunensis,

Cryptotermes domesticus,

Hodotermopsis japonica,

Reticulitermes miyatakei,

Odontotermes formosanus,

Nasutitermes takasagoensis,

Capritermes nitobei and so on.

The active compounds of the general formula (I) in the present inventioncan be prepared into the customary formulations, such as solutions,emulsions, suspensions, powders, foams, pastes, granules, aerosols,natural and synthetic materials impregnated with active compounds, andmicro-capsules.

These formulations may be produced in a known manner, for example, bymixing the active compounds with extenders, that is to say liquid orliquefied gaseous or solid diluents or carriers, optionally with the useof surface-active agents, that is to say emulsifying agents, dispersingagents, and/or foam-forming agents. In the case of using water as anextender, organic solvents can, for example, also be used as auxiliarysolvents.

As liquid diluents or carriers can be mentioned, for example, aromatichydrocarbons, such as xylene, toluene and alkyl naphthalenes,chlorinated aromatic or chlorinated aliphatic hydrocarbons, such aschlorobenzenes, chloroethylenes and methylene chloride, aliphatic oralicyclic hydrocarbons, such as cyclohexane or paraffins, for example,mineral oil fractions, alcohols, such as butanol or glycol as well astheir ethers and esters, ketones, such as acetone, methyl ethyl ketone,methyl isobutyl ketone or cyclohexanone, or strongly polar solvents,such as dimethylformamide and dimethylsulfoxide, as well as water.

By liquefied gaseous diluents or carriers are meant liquids which aregaseous at normal temperature and under normal pressure, for example,aerosol propellants, such as halogenated hydrocarbons as well as butane,propane, nitrogen and carbon dioxide.

As solid diluents there may be used ground natural minerals, such askaolins, clays, talc, chalk, quartz, attapulgite, montmorillonite ordiatomaceus earth, and ground synthetic minerals, such ashighly-dispersed silicic acid, alumina and silicates.

As solid carriers for granules there may be used crushed andfractionated natural rocks such as calcite, marble, pumice, sepioliteand dolomite, as well as synthetic granules of inorganic and organicmeals, and granules of organic material such as sawdust, coconut shells,maize cobs and tobacco stalks.

As emulsifying and/or foam-forming agents there may be used nonionic andionic emulsifiers, such as polyoxyethylene-fatty acid esters,polyoxyethylene-fatty alcohol ethers, for example, alkylaryl polyglycolethers, alkylsulfonates, alkylsulfates, arylsulfonates as well asalbumin hydrolysis products. Dispersing agents include, for example,lignin sulfite waste liquors and methyl cellulose.

Adhesives such as carboxymethyl cellulose and natural and syntheticpolymers, (such as gum arabic, polyvinyl alcohol and polyvinyl acetate)can be used in the formulations in the form of powders, granules oremulsifiable concentrations.

It is possible to use colorants such as inorganic pigments, for example,iron oxide, titanium oxide and Prussian Blue, and organic dyestuffs,such as alizarin dyestuffs, azo dyestuffs or metal phthalo-cyaninedyestuffs, and trace elements, such as salts of iron, manganese, boron,copper, cobalt, molybdenum and zinc.

The formulations, in general, contain from 0.001 to 95 percent by weightof active compound, preferably from 0.5 to 90 percent by weight.

Furthermore, the active compound of the present invention having theformula (I) can be present as a mixture with a synergist in aformulation or a use form, of the type that is commercially useful. Theterm “synergist” denotes a compound which is not active in itself, butpromotes the action of an active compound. The content of the activecompounds having the general formula (I) of the present invention inconmercially useful formulations can vary within a wide range. Theactive compound concentration.of the formulation for use is, forexample, from 0.0000001 to 100 percent by weight, preferably from 0.0001to 1 percent by weight.

In order to protect the above-mentioned materials completely, i.e. notonly against material destroying insects but also against fungi,bacteria and algae, they can be treated with compositions containing atleast one insecticidally active compound of the formula (I) and at leastone biological active fungicide, bactericide or algizide.

Wood or composite wood-materials can preferably be treated with acomposition containing

a) an insecticidally effective amount of a compound of the formula (I)or mixtures thereof and

b) a fungicidally effective amount of at least one compound selectedfrom the group of

Trihalosulfenyl-Compounds such as

N-Dichlorofluoromethylthio-N′,N′-dimethyl-N-phenyl-sulfuric acid diamide(Dichlofluanide)

N-Dichlorofluoromethylthio-N′,N′-dimethyl-N-p-toluylsulphamide(Tolylfluanide)

N-Trichloromethylthiophthalimide (Folpet)

N-Dichlorofluoromethylthiophthalimide (Fluorfolpet) etc.

Iodine-Compounds such as

3-Iodo-2-propynyl-butylcarbamate (IPBC)

3-Iodo-2-propynyl-hexylcarbamate

3-Iodo-2-propynyl-cyclohexylcarbamate

3-Iodo-2-propynyl-phenylcarbamate

Diiodmethyl-p-tolylsulphone (Amical 48) etc.

Phenols such as

ortho-Phenylphenol

Tribromophenol

Tetrachlorophenol

Pentachlorophenol etc.

Azole-Compounds such as

1-(4-Chlorophenoxy)-3,3-dimethyl-1-(1H-1,2,4 triazol-1-yl)-2-butanone(Triadimefon)

β-(4-Chlorophenoxy)-α-(1,1 dimethyl-ethyl)-1H-1,2,4 triazole-1-ethanol(Triadimenol)

±α[2-(4-chlorophenyl)ethyl]-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol (Tebuconazole)

1-[2(2,4-dichlorophenyl)4-propyl-1,3-dioxolan-2-ylmethyl]-1H-1,2,4-triazole (Propiconazol)

1-[2(2,4-dichlorophenyl)-1,3-dioxolan-2-ylmethyl]-1H-1,2,4-triazole(Azaconazol)

(RS)-2(2,4-dichlorophenyl)-1-(1H-1,2,4 triazol-2-yl)-2-ol (Hexaconazol)

1-N-propyl-N-[2-(2,4,6-trichlorophenoxy) ethyl] carbamoylimidazol(Prochloraz) etc.

Tin Compounds such as

Tributyl tin octoate

Tributyl tin oleate

Bistributyl tin oxide

Tributyl tin naphthenate

Tributyl tin phosphate

Tributyl tin benzoate etc.

Thiocyanate Compounds such as

Methylenebisthiocyanate (MBT)

2-Thiocyanomethylthiobenzothiazole (TCMTB) etc.

Quarternary Ammonium Compounds such as

Benzyl-dimethyl-tetradecylammoniumchloride

Benzyl-dimethyl-dodecylammoniumchloride etc.

Benzimidazole Compounds such as

2-(2′-Furyl)-1H-benzimidazole (Fuberidazole)

Methylbenzimidazol-2-ylcarbamate (BCM)

2-(4¹-thiazolyl) benzimidazole (Thiabendazole)

Methyl (1-butylcarbamoyl)-2-benzimidazole carbamate (Benomyl)

Isothiazolinone Compounds such as

N-Methylisothiazolin-3-one

5-Chloro-N-methylisothiazolin-3-one

4,5-Dichloro-N-octylisothiazolin-3-one

N-Octylisothiazolin-3-one

Morpholine Compounds such as

C₁₄-C₁₁-4-Alkyl-2,6-dimethylmorpholine (Tridemorph)

Pyridine Compounds such as

1-Hydroxy-2-pyridine-thione and Sodium Iron, Manganese or Zinc-Saltthereof

Tetrachloro-4-methyl sulphonyl pyridine

N-Cyclohexyldiaziniumdioxy Compounds such as

Tris-(N-cyclohexyldiaziniumdioxy) aluminium

Bis-(N-cyclohexyldiaziniumdioxy) copper

Naphthenate Compounds such as

Zincnaphthenate

Quinoline Compounds such as the cooper salt of

8-hydroxy-quinoline

Nitriles such as

1,2,3,5-Tetrachloro-4,6-cyanobenzene

Boric compounds such as boric acid, borax, borates

Ureas such as N′(3,4-dichlorophenyl)-N,N-dimethylurea

Furane derivatives such as Furmecyclox

These fungicidally effective compounds are added to the composition inorder to prevent wood or wood materials not only against wood destroyinginsects but also against

Wood-discoloring fungi such as

Ascomycetes (Caratocystis minor)

Deuteromycetes (Aspergillus niger, Aureobasidium pullulans, Dactyleumfusarioides, Penicillium Variabile, Sclerophoma pithyophila, Scopulariaphycomyces, Trichoderma viride, Trichoderma liguorum)

Zygomycetes (Mucor spinosus)

and/or

Wood-destroying fungi such as

Ascomycets (Chetomium alba-arenulum, Chaetonium globosum,

Humicola grisea, Petriella setifera, Trichurus spiralis)

Basidiomycetes (Coniophera puteana

Coriolus versicolor

Donbiopora expansa

Glenospora graphii

Gloeophyllum abietinum

Gloeophyllum adoratum

Gloeophyllum protactum

Gloeophyllum trabeum

Gloeophyllum sepiarium

Lentinus cyathioformes

Lentinus edodes

Lentinus lepideus

Lentinus squavrolosus

Paxillus panuoides

Pleurofus ostreatus

Poria placenta

Poria monticola

Poria vaillantii

Poria vaporia

Serpula himantoides

erpula lacrymans

Tyromyces palustris)

Deuteromycetes (Cladosporium herbarum).

Generally the compositions also will include at least one additionaldiluent, emulsifier, melting agent, organic binding agent, auxiliarysolvents, processing additives, fixatives, plasticizers, UV-stabilizersor stability enhancers, dyes (water soluble, water insoluble), colorpigments, siccatives, corrosion inhibitors, antisettlement agents,additional insecticides (such as insecticidal carbamates,organophosphorus compounds, halogenated hydrocarbons, pyrethroidesetc.), anti skinning agents and the like.

The above-mentioned additional ingredients and their use are describedin prior art. (EP-A 0370665, DE-A 3531257, DE-A 3414244).

The compositions according to the present invention generally comprisefrom about 10⁻⁶ to 30 parts by weight, preferably from about 0.0005 to15 parts by weight and more preferably from 0.005 to 2 parts by weightof the insecticide of formula (I) and from 0.01 to 90 parts by weight,preferably from about 0.05 to 50 parts by weight and more preferablyfrom 0.1 to 30 parts by weight of at least one of the above-mentionedfungicides.

The compositions can be provided as ready for use products or asconcentrates, which have to be diluted prior to use.

The compositions can be applied by means of brushing, spraying, dipping,double vacuum and the like as known in the art. The compositions can beprepared by any technique known in the art.

The content of the present invention will be concretely explained by wayof the following examples but the present invention should not belimited only thereto.

EXAMPLES FOR COMPOSITIONS

*Remark: The Percentages are Given in Percent by Weight

Example 1

0.005% 1-(6-chloro-3-pyridylmethyl)-2-nitroimino-imidazolidine(imidacloprid)

5% Butylglycol

94.995% Mineral spirits

Example 2 Impregnating Agent/Primer

0.01% Imidacloprid

0.5% Dichlofluanide

1.% Tebuconazole

9.7% Alkyd resin (solid)

88.79% Mineral spirits

Example 3 Wood Stain/Low Build

0.01% imidacloprid

0.5% Dichlofluanide

1.2% Tebuconazole

21% Alkyd resin (solid)

2% Pigment

4% Antisettlement additive, dryes etc.

71.29% Mineral spirits

Example 4 Wood Stain/High Build

0.015% imidacloprid

0.6% Dichlofluanide

1.5% Tebuconazole

40% Alkyd resin

2% Pigment

4% Antisettlement additive, dryer etc.

48.115% Mineral spirits

Example 5 Soil Treatment

20% imidacloprid

8% ethylene glycol

3% emulsifiers

0.25% thickeners

68.75% distilled water

Example 6 Wood Brushing

0.1% imidacloprid

1% 3-bromo-2,3-diiodo-2-propenyl ethylcarbonate

98.9% organic solvents

Example 7 Wood Brushing

0.1% imidacloprid

1.5% 4-chlorophenyl-3-iodopropargylformal

98.4% organic solvents

Example 8 Formicidal Test

Compounds Under Test

Examples of the active compounds according to the present invention

I.1: 1-(6-chloro-3-pyridylmethyl)-2-nitromethylene-imidazolidine

I.2: 3-(6-chloro-3-pyridylmethyl)-2-nitromethylenethiazolidine

I.3: imidacloprid

Comparative Compounds

A: phoxim

B: chlorpyriphos

Preparation of Test Formulation:

Solvent: 3 parts by weight of xylene

Emulsifier: 1 part by weight of polyoxyethylene-alkylphenyl-ether

To prepare a suitable formulation of the active compound, 1 part byweight of each of the active compounds was mixed with theabove-mentioned amount of the solvent containing the above-mentionedamount of the emulsifier, and the mixture was diluted with water to apredetermined concentration.

Test Method:

1 ml of the aqueous solution prepared in the above-mentioned procedurewas uniformly applied using a pipette onto a filter paper that wasplaced in petri dish of 9 cm diameter. Ten head of worker termites(Coptotermes formosanus) were replaced into the petri dish and it waskept in a constant temperature chamber at 25° C.

After four days, the mortality of the termites was investigated. Thistest procedure was carried out in duplicate per each concentration ofthe active compounds under test.

The test results are shown in Table 1.

TABLE 1 Concentration of Mortality of termites active compound afterfour days Compound (ppm) (%) I.1 40 100 8 100 1.6 100 0.32 100 I.2 40100 8 100 1.6 100 0.32 100 I.3 40 100 8 100 1.6 100 0.32 100 A 40 100 8100 1.6 100 0.32 90 B 40 100 8 100 1.6 100 0.32 100 Untreated 0

Example 9 Test on Residual Effect

Small blocks of Japanese redpine tree (2 cm×2 cm×2 cm) were soaked forone minute into the aqueous solution prepared by the similar procedureto Example 8.

After air-dried, they were kept in a constant temperature chamber at 40°C. for four weeks. Then each of the thus treated blocks was placed in apolymeric cup (10 cm diameter) containing 150 ml of sandy loam of 20%moisture content. Into each of the polymeric cups, 100 head of workingtermites and 10 head of soldier termites (Coptotermes formosanus) werereleased. After three weeks, the degree of xylophagous damage in theblock and the mortality of the termites were investigated.

Three tests were carried out in duplicate 25° C., and the results areshown in Table 2.

The index of xylophagous damage observed on the test blocks:

0: No damage

0.5: One to two traces of damage each having a depth of about 1 mm fromthe block surface

1: One to two evident damages each having a depth from 1 to 2 mm fromthe block surface

2: More than three evident damages or more than one deep trace of damagehaving a depth of more than 2 mm from the block surface

3: More than three deep damages

4: Evidently damaged zone covering up to about one third of the wholesurface area of the block

5: Evidently damaged zone covering more than one third of the wholesurface area of the block

TABLE 2 Degree of Concentration Mortality xylophagous of active termitesafter damage in the pine Compound compound (ppm) three weeks (%) treeblock (0-5) I.1 40 100 0 8 100 0 1.6 100 0 0.32 98 0.5 I.2 40 100 0 8100 0 1.6 100 0 0.32 100 0 I.3 40 100 0 8 100 0 1.6 100 0 0.32 100 0 A40 25 3 8 0 5 1.6 0 5 0.32 0 5 B 40 100 0 8 78 1 1.6 0 3 0.32 0 5Untreated 0 5

Example 10 Toxic Value Against Larvae of Hylotrupes bajulus

The toxicity against larvae of Hylotorupes bajulus, using wood samplestreated with the active compound I.3 provided in Example 8 in chloroformhaving concentrations of 1.44×10⁻⁵%, 1.44×10⁻⁴%, 7.2×10⁻³%, and1.44×10⁻²% was determined according to the detailed description of DINEN 47 (edition 1990, Beuth Verlag GMBH) which is concerned with theEuropean standard method prescribed by the European Committee forstandardization concerning wood preservatives, determination of thetoxic value against larvae of Hylotrupes bajulus.

An outline of the method is as follows: (see DIN EN 47 for detail)

Five wood-samples (50 mm×25 mm×15 mm) which are treated by the activecompound beforehand (impregnation treatment in vacuum) are provided andin each specimen, a regular pattern of six holes are bored, and then onehead of the larvae is inserted per a hole.

After four weeks, the specimens are cut up in turn and the number oflive/dead of larvae is determined.

In determination, where a live larvae is identified in a specimen, thenthe remaining specimens without cutting up are stored for a furthereight weeks, and afterward, the number of live/dead larvae isdetermined.

From this test, the Toxic threshold value was between 1.08 g/m³ and 10.8g/m³ of the active compound I.3.

The results are shown in Table 3.

TABLE 3 Concen- Quantity State of the larvae at the end of Durationtration of active compound the test of the of the concentrate absorbedin deed test in impregnating g/m³ wood no wood wood not weeks solution(%) min. max. M-value digested digested living found 4 0.0144 82.08116.64 103.97 27 3 0 0 0.0072 45.36 56.88 52.85 29 1 0 0 0.00144 10.0811.23 10.80 4 6 1 1 (*1) 12 0.00144 9.94 11.66 10.80 6 11 0 1 (*2)0.000144 0.95 1.21 1.08 4 12 11 3 0.0000144 0.09 0.12 0.11 1 4 23 2 12control impregnated with 2 2 24 2 samples chloroform not treated

Note:

(*1) One live larvae was found in the second specimen.

(*2) The remaining three specimens were tested for further eight weeks(12 weeks in total).

Comparative values of W. Metzner et al in “Holz als Rohund Werkstoff, 35(1977) 233-237”, table 6 on page 236.

TABLE 4 Insecticide toxic value (g/m³) Insecticide toxic value (g/m³)DDT  5-10 Bassa (Baycarb) 17-30-44 Diazinon 12-18-32 Propoxur 18-30Phoxim  7-12 Carbaryl 12-18 Chlorophoxim 12-20-32

Example 11 Effectiveness Against the Termite Species Reticulitermessantonensis

The toxicity against Reticulitermes santonensis of solutions containingthe active compound I.3 in chloroform having the concentrationsmentioned in Example 10 was determined according to the detaileddescription of DIN EN 117 Edition 1981 which is concerned with theEuropean standard method prescribed by the European Committee forstandardization concerning wood preservatives, determination of thetoxic value against Reticulitermes santonesis.

An outline of the method is as follows: (see DIN EN 117 for detail)

The same three wood-samples with impregnation treatment in vacuum as inExample 10 are provided.

They are exposed to 250 workers, 1 soldier and 1 nymph per batch foreight weeks, and afterward, the number of live/dead larvae isdetermined.

From this test, the toxic threshold value was between 0.135 g/m³ and1.344 g/m³ of the active compound I.3.

The evaluation was made by the following standard:

*Rating Values:

0=no attack

1=attempted attack

2=slight attack

3=average attack

4=strong attack

The results are shown in Table 5.

TABLE 5 Quantity of Quantity of protective agent Concentration solutionabsorbed Results of evaluation of protect absorbed average sur- agenttested No. of per wood per wood quantity viving Soldiers (S) in % woodsample sample absorbed workers or (m/m) sample in g/m³ in g/m³ in g/m³ %nymphs (N) * rating 1.44 × 10⁻⁵% 1 17.75 0.136 0.135 55 S/N 4 2 17.470.134 51 S/N 4 3 17.69 0.136 58 S/N 4 1.44 × 10⁻⁴% 4 17.75 1.363 1.344 0— 1 5 17.39 1.336 0 — 1 6 17.37 1.334 0 — 1 1.44 × 10⁻³% 7 17.54 13.47113.463 0 — 1 8 17.56 13.486 0 — 1 9 17.49 13.432 0 — 1 7.20 × 10⁻³% 1017.29 66.3936 68.211 0 — 0 11 18.03 69.2352 0 — 0 12 17.97 69.0048 0 — 01.44 × 10⁻²% 13 17.79 136.627 136.627 0 — 0 14 17.72 136.090 0 — 0 1517.86 137.165 0 — 0 control samples 16 17.72 0 0 50 —/N 4 diluent 1718.15 0 57 S/N 4 (chloroform) 18 17.77 0 48 S/N 4 control samples 19 0 00 55 S/N 4 untreated 20 0 0 62 S/N 4 21 0 0 64 —/N 4

Comparative values of W. Metzner et al in “Holz als Rohund Werkstoff,”35(1977) 233-237, table 10 on page 236.

TABLE 6 toxic value toxic value Insecticide g/m³ Insecticide g/m³DDT >1500 Chlorophoxim 500 Dieldrin 50 Bassa 500 Lindan 75 Propoxur 140Ethylparathion 200 Carbaryl 1100 Phoxim 400

What is claimed is:
 1. A method of protecting a wood product selectedfrom the group consisting of wood and wood composites against attack byinsects comprising applying directly thereto an amount sufficient toeffect protection thereof of the compound1-(6-chloro-3-pyridylmethyl)-2-nitroimino-imidazolidine, wherein saidcompound is applied in manner selected from the group consisting of i)soaking said wood product in or with said compound, ii) impregnatingsaid wood product with said compound, iii) brushing said compound ontosaid wood product, iv) spraying said compound onto said wood product,and v) dipping said wood product in said compound and wherein afterthree weeks said imidazolidine compound shows improved long lastingeffects.
 2. A method according to claim 1, wherein the1-(6-chloro-3-pyridylmethyl)-2-nitroimino-imidazolidine is in the formof a composition comprising from 10⁻⁶ to 30 parts by weight of1-(6-chloro-3-pyridylmethyl)-2-nitroimino-imidazolidine.
 3. A methodaccording to claim 1, wherein the1-(6-chloro-3-pyridylmethyl)-2-nitroimino-imidazolidine is in the formof a composition comprising from 0.32 to 40 ppm1-(6-chloro-3-pyridylmethyl)-2-nitroimino-imidazolidine.
 4. A methodaccording to claim 1, wherein the wood product is a wood compositeselected from the group consisting of pressed wood, particle board, chipboard, plywood and wood laminated materials.